postgres_fdw: Remove redundant check in semijoin_target_ok()

akorotkov · akorotkov · commit c5cf99e9e52e · 2025-03-25T12:49:14.000+02:00
If a var belongs to the innerrel of the joinrel, it's not possible that it belongs to the outerrel. This commit removes the redundant check from the if-clause but keeps it as an assertion. Discussion: https://postgr.es/m/flat/CAHewXN=8aW4hd_W71F7Ua4+_w0=bppuvvTEBFBF6G0NuSXLwUw@mail.gmail.com Author: Tender Wang <tndrwang@gmail.com> Reviewed-by: Alexander Pyhalov <a.yhalov@postgrespro.ru> Backpatch-through: 17
diff --git a/contrib/postgres_fdw/postgres_fdw.c b/contrib/postgres_fdw/postgres_fdw.c
@@ -5758,15 +5758,15 @@ semijoin_target_ok(PlannerInfo *root, RelOptInfo *joinrel, RelOptInfo *outerrel,
 		if (!IsA(var, Var))
 			continue;
 
-		if (bms_is_member(var->varno, innerrel->relids) &&
-			!bms_is_member(var->varno, outerrel->relids))
+		if (bms_is_member(var->varno, innerrel->relids))
 		{
 			/*
 			 * The planner can create semi-join, which refers to inner rel
 			 * vars in its target list. However, we deparse semi-join as an
 			 * exists() subquery, so can't handle references to inner rel in
 			 * the target list.
 			 */
+			Assert(!bms_is_member(var->varno, outerrel->relids));
 			ok = false;
 			break;
 		}
